Electrochemical detection of nitrate ions via reduction of NO2−and oxidation of NO reactions based on Cu@TiO2 coreshell/nafion/polyalizarin immobilized electrode

Abstract

In this paper, we synthesized Cu nanoparticles and Cu@TiO2 core–shell. Regarding the characterization of the Cu nanoparticles and Cu2O@C core–shell, the transmission electron microscopy (TEM), ultraviolet (UV) absorption spectrum, dynamic light scattering (DLS) and zeta potential techniques were employed. The Cu@ TiO2 core–shell with conductive polymers such as Nafion (Nf) and Polyalizarin yellowe R (PAR) immobilizing on glassy carbon electrode (Cu@TiO2-Nf/PAR/GCE). This was used for fabrication of an original electrochemical sensor to measurement nitrate via reduction of NO2− and oxidation of NO reactions. Cyclic voltammetry and impedimetric techniques were employed to confirm the novel sensor construction. Other electrochemical analysis was done by cyclic voltammetry and differential pulse voltammetry methods. The results shed lights on the matter that, Cu@TiO2-Nf/PAR/GCE composite has a great electrocatalytic effect for detecting and determining nitrate ion at −0.8V(Red2) and 0.9V(OX). Linear range, sensitivity and limit of detection were calculated for two area potentials.